My LO was bottle fed, and always woke for the DF. Like ali says you can try a different time to catch him in deeper sleep.
Eventually mine habitually woke for the DF so would wake a few mins earlier in anticipation of the feed - just meant I had to be on time - further down the line when you need to ween the DF you have to accept LO is awake so treat it like a NF. It wasn't hard even though I was quite nervous about it.